Which is the most practical for daily/weekend driving? Can I run either on pump gas? These questions are with the assumption that all parts are equal and the engine was built with all this in mind.

 

Turbocharging is superior to supercharging.


It's the most practical way to go fast.


Supercharger's cause parasitic drag on your drive train, cause they are belt driven.


Turbocharging basically runs off of exhaust gases and is much more efficient at making power. Depending on the size of the turbo's will be how responsive the system is with something that will spool up very quickly or something that will take some RPM to spool up but make more power on the big end.


You can run either on pump fuel.

 

For daily/weekend driving a turbo would deffinatly be the best of the two options. You have to run lower compression. you will also have some reasonable fuel economy but still get it when you step on it. Going to be hard running on pump gas. You would need to have 8:1 compression and about 6 lbs of boost to stay with pump. If you go with a good electronic injection that can control the ignition or at least a water injection you could have more boost or compression.

Our 62 Jetfire has 10:1 compression with 7 lbs of boost but it is water injected from the factory. Only a 215 engine but you sure know it has a turbo when you step on it.

 

Im not sure if I agree with the loss of hp to run a blower I would agree with a blower specially roots type will cost more. The blower will make hp on tap and not have boost lag although it will eat a few ponies. I do agree that turbos are the way to go for the street specially since stuff can be had cheap depending on your taste and it will probably run you cheaper than trying to run a roots type blower. I think if you ran a centrifugal it would be cheaper that a roots type but since oldsmobiles are limited to aftermarket stuff custom bracketry comes to mind. The turbos can be place anywhere pretty much., you can have an exhaust shop bend some pipe and really do most of it with out special parts so to speak.

 

Copper, I don't mean to bust your chops, but you should re-read your posts before you press the "Submit" button. This is what makes some of the other guys get on your case sometimes.

The power difference between a supercharger and a turbocharger is that a supercharger takes power from the crankshaft, and thus from the rear wheels, while a turbocharger takes power from the heat in your exhaust that you were going to throw away anyway.

Both add power to your engine, so that when all is said and done, you have more power with either one, but the turbo is more efficient, as it extracts less of an expense in power, compared to its return of extra power.

Because of this, a turbo is slightly more fuel efficient.

- Eric

 

MD.. actually, Copper has the right of it. The supercharger does take a few horses all the time at the crank ... but it also is on all the time so the hp it takes is from the already boosted state ... so in the end, there is no actual loss. There is increased fuel consumption tho. Oldskool ... you neglect to mention important details such as vehicle, carb or injection ... computer or not ... even age of the car. Practicality is more than just the horses you make ... it's how easy is it to fix when something breaks, how many thousands of dollars to install ... and extra gallons of high octane to run.


A super is like having more displacement. You get more efficiency from the cubes you have without shoehorning a 455 under the hood. A turbo is like adding nitrous ... more power only when your right foot gets heavy .... but like nitrous, most turbo engines take a beating since few people take the time to strengthen them before throwing that extra power down it's throat. The ignition advance for a super is pretty easy to work with ... setting it on a turbo is like trying to use one timing on two different engines at the same time.


Installing is another headache. You might have room under the hood to install a turbo ... but Gawd help you next time you have to pull a sparkplug. There's a reason SC stacks often involve a qaping hole cut in the hood. Tailpipe turbos have added a new dimension to that discussion ... but to me they sound like ***.

 

I've tuned many EFI'd turboed and supercharged applications and the spark maps tend to look very similar. If you have 5# of boost either with a turbo or supercharger then you'll need about the same amount of fuel and spark, with the only potential difference being the temperature of the incoming air. Apples to apples the new superchargers (Procharger, Vortech) tend to heat the air less than the old roots style. That's a big plus in both hp and and reliability.

 

Eric what. Meant was I don't agree with that blanket statement that the blower will eat up hp to the point it will under perform . It will eat some power but not enough imo to rule it un superior to the turbo . Let's not forget top fuel is still using huffers. I personally like turbos from a weekend warriors point of view.


Edit: I know where I can sound contradiciting in that post but its hard not to . On one hand someone said the turbo is superior and imo it's great but until its on top fuel not superior. Using the statement that a blower will eat up hp to pin it against a turbo is the wrong argument which is how I saw it. Turbos have lag which is great for a street car because it wont shock the suspension with all that power meaning a 10 sec. boosted car will need minimal suspension mods but it wont make the tq. the blower will on tap so on the street you will have a really mild mannered ride with the turbo until you spool up. There is a few pros and cons to both and there are many reason to go both but for a street strip ride you cant beat the turbo for the fact that you can get great mpg since you wont need all the extra fuel to feed those extra cubes and you can make great hp and not need so much suspension work.

 

I know what you meant, Copper. Like I said, not trying to bust on you, just pointing out that the way you wrote it, it could be confusing (or bait for someone who wants to argue).

And Prof., you can always put an A/C clutch on a supercharger.

- Eric

 

Or you could get a supercharger like Mel Gibson had in Mad Max, with a shifter. :/??? Ahh holly weird you make up reality as you go

 

Supercharging is a generic term that means using some method to increase intake air pressure above atmospheric. Turbocharging is a form of supercharging that uses an exhaust gas driven turbine to spin the compressor. The more common supercharger is mechanically driven off the engine.

Both have advantages and disadvantages depending on the application and intended use - there is no absolute "one is better than the other". As noted a mechanically driven supercharger requires HP to turn the compressor, but since the unit is mechanically driven, there is no boost lag so low end performance is improved. You can get the same low end boost from a turbo by using a smaller unit, but at the expense of total top-end power. There are clutch-actuated superchargers (some of the factory-installed units have clutches like A/C compressors) to avoid this HP loss when the boost isn't needed. There are variable geometry turbine scrolls to improve low-end turbo performance.

Bottom line is that there is no absolute.

 

Fi yes, nitrous is more sudden than a turbo, but a SC doesn't suddenly pile on more power at 3000rpm at all... therefore turbo and nos are more similar. As you said ... a well done turbo can be gradual .... Just like a well done turbo or nos install will include strengthening. It's not been my experience that the average aftermarket kit install is well done. Maybe you've got a better class of shade tree wrench monkey. As for the ignition, programming a computer for a turbo or SC and trying to tweak a vacuum advance and weights for a points distributor to give a smooth daily drive aren't what I call comparable. Not knowing what vehicle the op is discussing kinda leaves that open.

 

Was considering procharger but wanted to see what options are out there for a 72' cutlass 350.

 

It is hard to make the math work on a street blower for an Oldsmobile, IMO. I tried. 5 lbs of boost is (roughly) 100 ft/lbs and 75 HP for a price tag of around $5000. Very hard to find used parts for Oldsmobiles. The bottom line is that from start to finish, you can build a 496 cheaper than a blown SBO with less hassles, easier tuning, and the same or better performance. Now, max build on race gas, different story. Turbos, howerer, can be pieced together if you are handy with that stuff and can tune it. But again, IMO, 5-6 lbs of boost for the street just isn't worth the trouble.

 

Good point capt, I concur it wouldn't be worth the expense or hassle. I keep trying to find an angle that'd allow me to get the most out of what I've already got , but I guess there's no way around it. Either keep my 350 as is or go all out on a bbo. 496, break it down for me Barney style, how do you make a 455 into a 496? Could it be suitable for daily/weekend driving , or strictly track?

 

I'm no BBO expert, in fact I've never built one, I like the 350s. A 496 is a bored 455 with a stroked crank. But, the reality is that a stout 455/468 is more than plenty for most street cars. Heck, a well thought out 380 is a great street engine. Really, what do you need?

 

Get your checkbook out.

http://coloradospeedcompany.com/Olds...rchargers.aspx

or

https://www.facebook.com/pages/Ultim...45677135508968

 

The spark adjustment you have with most EFI systems isn't comparable with any distributor with weights, springs and a vacuum advance. It's far superior, whether it's normally aspirated or boosted, doesn't matter. You said that a SC application will have different curve than a turboed one. Not true, they typically won't. Again unless of course there is an air temp difference in the two applications.

You have your comparisons all mixed up, sorry.